[ECOS] Re: Idle timeout and maximum # of sockets for athttpd

["Anthony Tonizzo" <atonizzo@gmail.com>]

> I don't quite understand CYG_HTTPD_SOCKET_IDLE_TIMEOUT
> in detail, but it is hardwired to 300 seconds which appears to be
> rather long for the default maxim # sockets (16).

The time of 5 minutes before an inactive socket is closed was
chosen without much concern to the maximum number of
sockets. Its intentions were mainly to close sockets that have
been inactive for more than 5 minutes, regardless of the reason:
In other words I felt that with persistent connections (and very
few sockets available to begin with) it is important to reclaim
any and all resource you might think are not actively used.

The sockets might be dead, or the user of the client might just be
enjoying a sandwich before she comes back surfing: Either way
if the socket is idle for 5 minutes I want to be able to reclaim it for
connections that actually carry some traffic.

We can make a case for making this a CDL option..

> Could CYG_HTTPD_SOCKET_IDLE_TIMEOUT be set to 0?
> What would happen?

I can interpret this question two ways:

1) CYG_HTTPD_SOCKET_IDLE_TIMEOUT equal 0 means that
there is no timeout (i.e. remove the call to
cyg_httpd_close_unused_sockets(). In this case the sockets will
be opened forever. You are now at the mercy of the stack to
determine that a socket is dead. Might work, but I have not
experimented with it. Now, your delay is even more hardcoded
(this time inside the stack itself.)
2) CYG_HTTPD_SOCKET_IDLE_TIMEOUT is active and equal 0
in which case, with the current code you would effectively resort
to closing each connection after the request was served. In other
words, you void the advantages of persistent connections by
reverting to HTTP 1.0. If you think 16 sockets are not enough
with persistent connections you will hate the alternative, where a
single web page with a lot of pictures can exhaust the number of
sockets.

Tony

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss